Signals and 4 Track Layout - can you advise please

[Norski]

Hi - hopefully a straight forward one.

 

Im running 4 lines in one part of layout. 2 up and 2 down lines (im no jargon expert so apologies). Ive got some Train-Tech signals on my layout and id like to use them on the 4 track arrangement -  Im not a slave to following real life but i try to keep at least plausible to me (im the only one looking at it).

 

On real life 4 tracks are signals ever positioned between the two centre rails or are they only ever on an overhead gantry?

 

Tried looking on line but not getting anywhere. Only twin track locally so i can't even go for a nose. Layout is based late 80s early 90s (im not setting any new trends ).

 

Many thanks.

 

 

[Grovenor]

Depends on the space available between the tracks, straight post signals were always preferred to gantries if they could be fitted in.  Look at these, majority are on Gantries but many are not.

http://www.norgrove.me.uk/signalling/plans/Euston-a.gif

http://www.norgrove.me.uk/signalling/plans/Willesden-b.gif

http://www.norgrove.me.uk/signalling/plans/Watford-a.gif

[Norski]

25 minutes ago, Grovenor said:

Depends on the space available between the tracks, straight post signals were always preferred to gantries if they could be fitted in.  Look at these, majority are on Gantries but many are not.

http://www.norgrove.me.uk/signalling/plans/Euston-a.gif

http://www.norgrove.me.uk/signalling/plans/Willesden-b.gif

http://www.norgrove.me.uk/signalling/plans/Watford-a.gif

 

Thank you. Great - So if im in the cab i could expect to see a post signal on my left (if im on far left) and to my right if im on the faster line. Space permitting. Good, i like the gantries and train-tech sell light kits to add to gantries but that's out of my skills zone (and probably eyesight) now.

Cheers

[Dagworth]

14 minutes ago, Norski said:

 

Thank you. Great - So if im in the cab i could expect to see a post signal on my left (if im on far left) and to my right if im on the faster line. Space permitting. Good, i like the gantries and train-tech sell light kits to add to gantries but that's out of my skills zone (and probably eyesight) now.

Cheers

Colour light signals on posts are always* on the left hand side of the line they apply to. 

 

So on a four track line you would get:

 

Paired by direction

                                      ---oooo

------------>---------------------------------------------

                                      ---oooo

------------>>--------------------------------------------

------------<<--------------------------------------------

                   oooo---

-------------<---------------------------------------------

                   oooo---

 

Paired by speed

                                      ---oooo

------------>----------------------------------------------

-------------<---------------------------------------------

                   oooo---      ---oooo

------------>>--------------------------------------------

------------<<--------------------------------------------

                   oooo---

 

Hope that makes sense

 

*ok, there may be exceptions but I cannot recall anywhere that I've ever seen one on the right

 

Andi

Edited March 2, 2021 by Dagworth

[Norski]

1 hour ago, Dagworth said:

Colour light signals on posts are always* on the left hand side of the line they apply to. 

 

So on a four track line you would get:

 

Paired by direction

                                      ---oooo

------------>---------------------------------------------

                                      ---oooo

------------>>--------------------------------------------

------------<<--------------------------------------------

                   oooo---

-------------<---------------------------------------------

                   oooo---

 

Paired by speed

                                      ---oooo

------------>----------------------------------------------

-------------<---------------------------------------------

                   oooo---      ---oooo

------------>>--------------------------------------------

------------<<--------------------------------------------

                   oooo---

 

Hope that makes sense

 

*ok, there may be exceptions but I cannot recall anywhere that I've ever seen one on the right

 

Andi

 

Very clear, perfect sense. Thank you. Just watching a cab view of class 91 on ECML and its exactly as you've shown.

Brill.Cheers Andi.

 

[TheSignalEngineer]

1 hour ago, Dagworth said:

*ok, there may be exceptions but I cannot recall anywhere that I've ever seen one on the right

The signals for "wrong direction" running on bi-directional lines are often placed to the right. 

Down direction on the Up Slow/Goods from Water Orton to Washwood Heath. The tracks were paired by direction and  many of the signal structures were cantilevers, so no suitable gantries to mount the signals on when the layout was altered in the mid-1980s.

The Trent Vally line has tracks paired by direction in the Rugby - Nuneaton - Lichfield area. The normal direction signals are placed as in your first example. The Fast lines can be used bi-directional and the signals for the wrong direction are placed in the wide interval to the right of the line in the direction of travel.

[Dagworth]

3 minutes ago, TheSignalEngineer said:

The signals for "wrong direction" running on bi-directional lines are often placed to the right. 

Doh, of course!  

 

Trying to remember if the signal on the Up Slow at Bromley South is (was) on the platform or on the normal side in the cess. 
 

Andi

Edited March 2, 2021 by Dagworth

[Michael Hodgson]

Quite common arrangement is to have 4-aspect on fast lines but only 3-aspect on slow.  This will depend on line speeds.

 

Two details illustrated by Dagworth but not explicitly noted :

1. if you have signals on one line, you would also have signals on the parallel line, as otherwise if it difficult for a driver to tell whether the   signal he is approaching applies to his line or the parallel one
2. You can put signal posts in the 10 foot, but it would be unusual to have them in the 6 foot.  Normal track spacing on a 4-track line is either

• 6 foot between the two tracks of each pair and 10 foot between the two pairs, or
• 10 foot between the two tracks of each pair but only 6 foot between the two pairs

       

 

 

[Norski]

9 hours ago, Michael Hodgson said:

Quite common arrangement is to have 4-aspect on fast lines but only 3-aspect on slow.  This will depend on line speeds.

 

Two details illustrated by Dagworth but not explicitly noted :

1. if you have signals on one line, you would also have signals on the parallel line, as otherwise if it difficult for a driver to tell whether the   signal he is approaching applies to his line or the parallel one
2. You can put signal posts in the 10 foot, but it would be unusual to have them in the 6 foot.  Normal track spacing on a 4-track line is either

• 6 foot between the two tracks of each pair and 10 foot between the two pairs, or
• 10 foot between the two tracks of each pair but only 6 foot between the two pairs

       

 

 

 

Ok. Thats a big help. Learn something knew every time I'm on here LOL -  Thanks

[St. Simon]

9 hours ago, Michael Hodgson said:

Quite common arrangement is to have 4-aspect on fast lines but only 3-aspect on slow.  This will depend on line speeds.

 

Two details illustrated by Dagworth but not explicitly noted :

1. if you have signals on one line, you would also have signals on the parallel line, as otherwise if it difficult for a driver to tell whether the   signal he is approaching applies to his line or the parallel one

 

Hi,

 

The common misconception is that the number of aspects is determined line speed, it isn't, the number of aspects is determined primarily by the required headway. Then, if the required headway says you only need 3 aspect, but the physical constraints mean that the spacing is too close for the linespeed, then the additional aspects are added (generally going from 3 to 4 aspects).

 

Whilst having parallel signals is much preferred, if the spacing, headway, overlaps, train protection etc means that you can't, then it is entirely legitimate to have 'out of sync' signals.

 

Simon

[Yardman]

Old school 4 and 3 aspect on a 4 track mainline.

[43110andyb]

I have added a line diagram of a section of the ECML between Thirsk and York. Mixture of 4 asp on fasts and 3 asp on slows, also shows track circuit info and where signalling location cabinets are positioned. 

[ReTyerd Signalman]

Part of the GCR main line east of Sheffield had main lines in the middle and goods lines on the outside.  However the only wide space was between the two main lines and some signal boxes had all the main line signals on the wrong side of the line.  In latter years the signals were a complete jumble of different styles of colour lights; 3 and 4 aspect multi-lens or searchlight.  Some had route indicators while others were multi-head junction signals.

[iands]

On 03/03/2021 at 21:27, 43110andyb said:

I have added a line diagram of a section of the ECML between Thirsk and York. Mixture of 4 asp on fasts and 3 asp on slows, also shows track circuit info and where signalling location cabinets are positioned. 

The IMDM diagrams, very useful information. I managed to get a copy before I retired.

[Suzie]

Wrong direction signals on the right of the track are a good way to find a use for those 2x yellow + green  distants. The wrong direction blocks can be much longer.

[WillCav]

1 hour ago, Suzie said:

Wrong direction signals on the right of the track are a good way to find a use for those 2x yellow + green  distants. The wrong direction blocks can be much longer.

They are often used for 3 to 4 aspect transitions as well. They are known as Wiltshire distants in NR.

 

Rarest one is a YGY combined with splitting distant just past West Drayton on the Up Relief.

 

Will